ADC Control Registers
725
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Analog To Digital Converter (ADC) Module
Table 19-9. ADC Calibration Mode Control Register (ADCALCR) Field Descriptions (continued)
Bit
Field
Value
Description
23-17
Reserved
0
Read returns 0. Writes have no effect.
16
CAL_ST
ADC Calibration Conversion Start. Setting the CAL_ST bit while the CAL_EN bit is set starts
conversion of the selected reference voltage. The ADC module uses the sample time configured in
the Event Group sample time configuration register (ADEVSAMP) for the calibration conversion.
Any operation mode:
1
Read: Calibration conversion is in progress.
Write: ADC module starts calibration conversion.
0
Read: Calibration conversion has completed, or has not yet been started.
Write: Writing 0 to this bit has no effect.
15-10
Reserved
0
Read returns 0. Writes have no effect.
9
BRIDGE_EN
Bridge Enable. When set with the HILO bit, BRIDGE_EN allows a reference voltage to be
converted in calibration mode.
defines the four different reference voltages that can be
selected.
8
HILO
ADC Self Test mode and Calibration Mode Reference Source Selection.
In the ADC Self Test mode, this bit defines the test voltage to be combined through a resistor with
the selected input pin voltage. Refer to
for details on the ADC Self Test Mode.
In the ADC Calibration Mode, this bit defines the reference source polarity. Refer to
for details on the ADC Calibration Mode.
In the ADC module’s normal operating mode, this bit has no effect.
7-1
Reserved
0
Read returns 0. Writes have no effect.
0
CAL_EN
ADC Calibration Enable. When this bit is Set, the input channel multiplexor is disconnected and the
calibration reference voltage is connected to the ADC core input. The calibration reference voltage
is selected by the combination of the BRIDGE_EN and HILO. The actual conversion of this
reference voltage starts when the CAL_ST bit is set. If the CAL_ST bit is already set when the
CAL_EN bit is set, then the calibration conversion is immediately started.
Please refer to
for more details on the ADC calibration mode.
Any operation mode read/write:
0
Calibration mode is disabled.
1
Calibration mode is enabled.